As advances are made in the technology for manufacturing integrated circuits, the capability and complexity of hardware and software for embedded systems increases. This continual increase in capability and complexity brings a continuing challenge for the software development tools used to create and debug applications for embedded hardware.
Embedded systems developers are facing a problem of “vanishing visibility”. It is increasingly harder to see in real time what's happening within an application, due to higher processor speeds, higher integration levels, and larger on-chip caches. “System-on-a-chip” solutions are incorporating more and more ASIC peripherals. Capabilities that used to be off-chip, and easily accessible for monitoring with logic analyzers, are now on-chip. The more traditional solutions of using logic analyzers and in-circuit emulators are quickly becoming insufficient to support the debugging needs of today's developers.
In recent years, a partial solution to this problem has been introduced. JTAG emulation has replaced in-circuit emulation. A JTAG test port is integrated into the microprocessor permitting data to be moved on- and off-chip without interrupting the executing device. And, in some microprocessors, this capability is augmented with additional emulation logic to provide even greater visibility and access into registers and other internal functions such as on-chip cache memories.
Some software tools have been created to aid the developer in using this enhanced debugging capability but they have tended to be rather primitive. These tools are usually designed to work with only one hardware design and must be partially to completely rewritten each time a new design is introduced. Given the pace of technology change, modifying software debug tools or creating new ones for each new hardware innovation in embedded systems is prohibitively expensive. As such, these system have a hardware centric view.
In addition, these software tools tend to be limited in their capabilities and in their ease-of-use. They have generally been created by hardware designers who think in terms of registers, comparators, addresses, etc. instead of in terms of the tasks or jobs the developer wishes to accomplish. In other words, the tools are hardware-centric rather than user-centric. The software developer has to be familiar with how the hardware works to accomplish even simple tasks such as setting a breakpoint.
Finally, the “system-on-a-chip” solutions are introducing a new problem for the developers and users of the software debug tools targets for these solutions. Hardware designs are no longer limited to a few, set configurations. Hardware designers can vary the capabilities of their “system-on-a-chip” to meet the needs of the target application. Therefore, to avoid requiring the software developers to learn a new hardware architecture and a new set of debug tools each time, the debug tools need to adapt themselves to the capabilities of the hardware.